Self-sharpening safety pin



P 1959 I P.'W. ZIEGENBEIN 2,904,865

SELF-SHARPENING SAFETY PIN Filed'Nov. 8, 1957 INVENT OR Paul W. Z/egenbe/n BY 0'5 V L ATTORNEY United States Patent' '0 SELF-SHARPENING SAFETY PIN Paul W. Ziegenbein, Norfolk, Nebr.

Application November 8, 1957, Serial No. 695,287 6 Claims. ((11. 24156) 9 My invention relates to improvements in safety pins.

A primary object of the invention is to provide a safety pin which is self-sharpening during use in the normal manner.

A further object of the invention is to provide means for automatically sharpening the pointed end of the mov able arm of the safety pin, as the same is moved into and out of the keeper or holder.

Another object of the invention is to apply abrading or sharpening means to the keeper or holder of a safety pm.

A still further object of the invention is to form the keeper or holder of the safety pin, in whole or in part, of an abrasive or grinding material.

Other objects and advantages of the invention will become apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a side elevation of a safety pin embodying my sharpening means.

Figure 2 is a transverse section taken on line 22 of v Figure 1.

Figure 3 is a longitudinal section taken on line 3-3 of Figure 1.

Figure 4 is a side elevation of a safety pin embodying a second form of sharpening means.

Figure 5 is a transverse section taken on line 55 of Figure 4.

In the drawings, wherein for the purpose of illustration are shown preferred embodiments of the invention, attention is directed first to Figures 1 to 3 inclusive, wherein the numeral 10 designates a safety pin as a whole, comprising arms or sides 11 and 12. The arms 11 and 12 are integrally connected with a coiled portion 13, at one end of the pin. The arms 11 and 12 and the coiled portion 13 are formed of metal which is suitably resilient, and the coiled portion 13 is resilient and is biased to move the arm 12 to the open position.

The arm 11 has its free end extending into a split sleeve 14, rigidly secured thereto by clamping engagement, or by other suitable means. The sleeve 14 is provided with integral flat extensions 15 and 16, depending therefrom in contacting relation, and secured together by any suitable means. The flat extension 15 is provided with a finger or stop 17, as shown.

The split sleeve 14 extends forwardly and downwardly, Figures 1 and 2, and its sides diverge downwardly and form a keeper or holder 18, which is U-shaped in cross section and open at its inner end. The finger 17 projects into the top of the keeper or holder 18, midway between its sides, as shown in Figure 2.

Mounted upon the keeper or holder 18 and covering the same is a body or layer of abrasive material, forming a grinding or sharpening element 19. The grinding or sharpening element may be formed of finely divided grinding material, such as Carborundum or diamond,

r" ice mixed with a suitable hardenable binder. The material employed for the grinding or sharpening element 19 of the safety pin may be applied to the keeper or holder 18 as a coating, in accordance with the teachings of United States Patent 2,308,624. If preferred, the grinding or sharpening element 19 may be molded about the metal keeper 18 so as to enclose the same, and the moldable material employed may be any conventional moldable abrasive or grinding composition.

The grinding or sharpening element 19 is U-shaped in cross section, and its sides are provided at their tops with longitudinally inclined faces 20. These faces are tapered longitudinally providing 'a passage increasing in width toward the forward end of the keeper or holder'18; The pointed end 21 of the resilient arm 12 is movable'into the grinding element 19 through the opening 22 afforded between the sides of thekeeper. The pointed end21 of the arm 12 will assume the lowered position indicated in Figure 2 when the safety pin is closed.

When the arm 12 of the safety pin has itspointed end 21 introduced into the keeper 18 carrying thegrin'd ing 0r sharpening element 19, such pointed end is'first' brought into contact with one outer side of the grinding element 19 and has slidable contact therewith and is moved upwardly and over the inclined edge 20 of the grinding element, while contacting therewith, and is then' introduced into the cavity of the-grinding element 19, while' slidably contacting the inner surface of one side of the same. A reverse operation of the arm 12 is employed to disengage the pointed end 21from within the grinding element 19, and during this reverse operation, there is a sliding contact between the pointed end 21 and the surfaces of the gr ind ing element 19. It is thus seen that the pointediend 21 is ground or sharpened automatically whenever it is introduced into or removed from the gaming element'19 carried by the safety pin keeper 18. The pointed end 21 maybe passed into the grinding element 19 upon either side of the finger or stop 17, asis thefca'se with most conventional safety pins.

In Figures 4 and 5 of the drawings, I have shown a modifiedform of safety pin embodying m'y invention.

7 This safety pin includes the same s'ides or 12 and the coiled portion 13. The separat eke er rholder 18 is dispensed with. In the second the' inv'em tion, I provide a keeper or holder s; ich {may be molded from any suitable moldab le bras containing material, such as a plastics material; containing finely divided Carborundum, diamond particles or the like. The keeper or holder 23 may also be formed of stone having suitable grinding properties. The integral keeper or holder 23 may be molded upon the forward end of the arm 11, which has a downturned extension 24, generally in accordance with the teachings of United States Patent 2,730,439, or in other conventional manners. The grinding keeper or holder 23 is provided with a recess 25 and has a closed side 26, and an opposite side 27 provided with a bead 28, which has a rounded surface 29. This head is longitudinally inclined and extends downwardly toward the inner end of the keeper 23. The bead 28 has its upper surface circularly curved and the bead is spaced from the top of the recess 25, providing a side opening 30.

It is thus seen that I have provided a keeper or holder which is integral and is formed of a grinding or abrasive material, and this keeper or holder is rigidly secured to the safety pin arm 11. The pointed end 21 of the arm 12, when outwardly of the recess 25 is brought into engagement with the outer surface of the side 27, bead 28 and surface 29, and slidably contacts therewith when being shifted inwardly through the opening 30 and into the recess 25. During this movement, the pointed end 21 has slidable contact with the grinding or abrasive surfaces of the keeper or holder 23 and is thereby automatically sharpened. When the pointed end 21 is to be shifted out of the recess 25, the same will be brought into contact with the inner surface of the side 27, bead 28 and surface 29, and will slidably contact these surfaces and will have an abrading action therewith, as the pointed end is being shifted outwardly through the side opening 30. It is thus seen that the pointed end 21 is sharpened by sliding contact with the surfaces of the keeper or holder 23 whenever the pointed end is being removed from or introduced into the abrasive keeper or holder.

It is to be understood that the forms of the invention herewith shown and described are to be taken as preferred examples of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, 1 claim:

1. A selfsharpening safety pin comprising a first arm, a generally U-shaped keeper carried by the first arm, a mass of abrading material covering the inner and outer faces of said U-shaped keeper, and a second arm having a pointed end connected with the first arm and shiftable into and out of the keeper and adapted to slidably engage the inner and outer faces of the keeper whenever the second arm is introduced into the keeper or disengaged therefrom.

2. A self-sharpening safety pin comprising a first arm, a keeper carried by said first arm, an abrasive coating upon the inner and outer surfaces of said keeper, and a second arm connected with the first arm and having a pointed end adapted to be sharpened by sliding contact with the inner and outer faces of the coated keeper whenever the safety pin is opened or closed in a normal manner.

3. A self-sharpening safety pin comprising, a first arm, a keeper carried by said arm and having a recess formed therein, said recess having an opening near its side, said keeper having the inner face of said recess embodying finely divided abrasive material, said inner face having a portion which is inclined longitudinally of the keeper and extends inwardly toward the outer end of the keeper, and a second arm connected with the first arm and movable laterally with relation to the first arm and having a free end tapered longitudinally toward the forward end of the keeper, the tapered end of the second arm being adapted to contact the inclined portion of the inner face and be sharpened by the inner face upon relative movement of the second arm with respect to the keeper.

4, A self-sharpening safety pin comprising, a first arm,

a keeper carried by said arm and having a recess formed therein, said recess having an opening near its inner side, said keeper having the inner face of said recess embodying finely divided abrasive material, said recess having; its forward end portion inclined in a longitudinal direc-- tion, and a second arm connected with the first arm and. movable laterally with relation to the first arm and hav-- ing its free end tapering forwardly toward the forwardi ends of the keeper, the tapered end of the second arm being adapted to contact with the inner abrasive face of the forward tapered portion of the recess and be sharp-- ened by said face upon the relative movement of the sec the first arm and shiftable laterally with relation to the first arm and having its free end tapered, said tapered end being adapted to contact said inclined portion and be sharpened by said inclined portion upon relative movement of the second arm with respect to the keeper.

6. A self-sharpening safety pin comprising, a first arm, a keeper carried by said arm and embodying finely divided abrasive material and a binder, said keeper having a recess formed therein and an opening leading into said recess, the abrasive material extending to the inner face of said recess, said inner face having an inclined portion, and a second arm connected with the first arm and shiftable laterally with relation to the first arm and having its free end tapered, said tapered end being adapted to contact the inclined portion and be sharpened by said inclined portion upon relative movement of the second arm with respect to the keeper,

References Cited in the file of this patent UNITED STATES PATENTS 157,981 Andrews Dec. 22, 1874 405,558 Jenkins June 18, 1889' 2,351,569 White June 13, 1944 2,551,063 Sneirson May 1, 1951 2,709,288 Munyer May 31, 1955 FOREIGN PATENTS 802 Great Britain 1894 20,729 Great Britain 1913 507,155 Great Britain June 9, 1939 

